UPDATE - And there it is. McCaskill again sheds her totally unconvincing "moderate" facade and caves to the left-wing of her party, which is where her heart has always been. Not only is she voting against Gorsuch, she's joining the filibuster, which makes it look like Schumer will probably get his 41. This is good news for conservatives. As for Claire, you know what to do, voters of a state that elected Trump by nearly 20 points:

The vote is slated for one week from today, at which point "undecided" Democrats' Hamlet routine will no longer be operative. Will they accede to the acerbic demands of the party's outraged base, or will they preserve the judicial filibuster for the next battle? Consider the case of Missouri's Claire McCaskill. She faces a tough re-election fight next fall in a state that Donald Trump carried by 19 points last year. She is a partisan liberal Democrat who masquerades as a moderate, having been an early Obama supporter in 2008, and then owning the distinction of becoming the very first member of Congress to formally endorse a presidential bid for Hillary Clinton. Obama lost her state twice, and Clinton got crushed there.

McCaskill cagily helped influence events by meddling in the GOP primary ahead of her last race, successfully hand-picking the opponent she felt most confident about beating; he promptly imploded, and she was re-elected. Her 2018 prospects look dimmer, which puts her in a bind: Does she enrage her core liberal voters and betray her own left-wing instincts by voting with Republicans to break Chuck Schumer's filibuster? Or does she take another high-profile vote in which she aligns with the hard left over the wishes of Missouri's conservative electorate? For now, she's walking a tightrope:

Sen. Claire McCaskill on Tuesday said she would not rule out voting to filibuster President Donald Trump’s Supreme Court nominee Neil Gorsuch. Democratic Senate Leader Chuck Schumer and at least 20 other Senate Democratshave said they’ll stage a filibuster to block an up-or-down vote on Gorsuch. McCaskill said Tuesday she is still doing her homework on Gorsuch and would say only that she supports the nominee getting at least a procedural vote on whether to quash a filibuster on the Senate floor. Under current Senate rules, that would take 60 votes. There are 52 Republican senators, meaning at least eight Democrats would have to vote against a filibusters for Gorsuch's nomination to proceed to an up-or-down vote.

Totally noncommittal. Plus, the notion that she's being "reasonable" by backing a procedural vote for a Republican nominee in a Republican-held Senate is risible. Then again, she seems to be telegraphing her concerns about blowing up the filibuster on Gorsuch in newly-released comments, in which she warns that such a move could empower President Trump and Senate Republicans to easily confirm additional justices over the next few years if vacancies open up as expected -- some of whom could be far worse than Gorsuch, from her perspective. This strategic thinking is arguably quite sound, as we've been arguing throughout this process. But her base doesn't want to hear it. A post at the left-wing blog Daily Kos is already raking her over the coals for her "delusional" equivocating:

Of all the tired, pathetic arguments Democrats have had over the years for not confronting Republican malfeasance, the idea that they have to keep their powder dry is the lamest. And it's that pathetic, misguided argument that Sen. Claire McCaskill (D-MO) seems to be making...That's just delusional. Does McCaskill know Mitch McConnell? Does she actually believe they could successfully filibuster the next "worse" one and he won't just go nuclear then? She witnessed McConnell lead an unprecedented and unprincipled and unconstitutional and unpatriotic total blockade of President Obama's nominee, Merrick Garland....McCaskill has a reputation as a canny politician back home. She sure as hell isn't displaying it in this argument. And by the way, "Gorusch was one of the better ones"?

Feel the rage, Claire. There are actual reasons why invoking the nuclear Reid Rule might be more difficult for McConnell to execute in a future confirmation fight, but don't listen to your head; listen to their angry hearts, Senator. By the way, let's take a peek at the unhinged diatribe about Republicans' treatment of Merrick Garland in that Kos rant, which claims that declining to consider Obama's lame duck nominee was "unprecedented, unprincipled, unconstitutional, and unpatriotic." First of all, it's always interesting to watch the Patriotism Police -- who tend to come unglued over any perceived suggestion that they may not love America as much as others, especially during the Bush years -- promiscuously hurl the "unpatriotic" epithet about at the drop of a hat. And such rhetorical excesses are (ahem) not limited to lefty fever swamp websites either. Also, if such a course of action violates one patriotic duty, someone from the Kos crew should make a citizen's arrest on Joe Biden.

Furthermore, the GOP-controlled Senate acted fully within its constitutional role by choosing not to entertain President Obama's election year nominee. In some cases, the upper chamber can fulfill the first half of its "advise and consent" duty through inaction. The "unprecedented" canard has been refuted several times, even as it continues to arise, including in more reputable publications. There ishistorical precedent for the Senate refusing to act on Supreme Court nominations, although this has been a rare occurrence. What actually would be unprecedented, however, is a partisan filibuster of a SCOTUS nominee, which has never happened in US history. Also unprecedented was Senate Democrats' nuking of the judicial filibuster in 2013 under a deeply dubious pretext, for which Republicans justifiably retaliated against the Garland nomination. And please, liberals, let's hear an indignant lecture about, uh, "principle:"

As another one of McCaskill's fellow red state Democratic colleagues announces her support for Neil Gorsuch, I'll leave you with a blue state Democrat muttering about the Court being "illegitimate" if a duly-nominated and -confirmed associate justice votes the "wrong" way in a 5-4 decision he doesn't like. That's not how any of this works, bro: